We propose to investigate three aspects of the complex phenomenon of follicular rupture. First, we plan to study how LH, the ovulation inducing-gonadotropin, sets in motion the series of changes within the ovarian follicle that ultimately lead to the enzymatic digestion of the apex of the ovulating follicle. Specifically, we will study the possible role of a) collagenolytic enzymes, b) plasmin and plasminogen activator, c) proteoglycanases in this process. Secondly, if one or more of these enzyme systems are shown to be involved in ovulation, we will attempt to determine how LH controls the enzyme activity. This will focus mainly on the role of prostaglandins, which has already been shown to play a key role in mediating the action of LH in ovulation. Thirdly, we will attempt to determine if the action of LH might also involve adenosine, which has been shown in other systems to amplify the action of LH. In many of these studies, we will make use of the model of in vitro perfusion of isolated ovaries obtained from immature PMSG treated rats. In this model, ovulation can be induced by the addition of LH to the perfusion medium. In addition, components of follicles (granulosa and theca cells) will be utilized in in vitro incubation and culture experiments. It is hoped that these studies will shed light on the mechanism of follicular rupture and will improve our understanding of this complex phenomenon. Ultimately, this may lead to better and more rational methods for promoting or inhibiting the process of ovulation by direct actions on the ovary itself.